also, if you look at the picture Raven is in, ALL of the other characters are playable.

We know Catwoman and Nightwing are playable. in the very back it looks like Cyborg vs someone offscreen, and Cyborg is playable.

Lex and Bane have been revealed, and while we haven't seen actual gameplay footage of them, the magazine did say Lex's "special button" gives him a shield and Bane's special button involves venom. That would suggest they are playable.

also, there was that rumor way back when about the voice actors for Cyborg, Deathstroke, and Raven, and the 1st 2 are confirmed playable. if Raven were merely a background/story/cutscene character, would she even need a voice actor??

so, with all of that, it should seem likely that Raven is playable. otherwise, that would be an extremely cruel and ironic tease to include her in that scene with other playable characters but make her unplayable.........